Hi, my name is McKenzie and I am in my third year at Trinity University in San Antonio, TX. I have spent the last two summers working with lizards and I would like to tell you about a cool project I worked on this past summer.
When an animal takes in energy (by eating food), it then can use this energy for all sorts of different reasons — for example, to keep its heart beating, or to run away from predators. The lizards we study in our lab use most of their energy for things like breathing, digesting food, growing, and flirting. They lose energy in their pee and poop (scientists call this “excretion”), and in the skin they shed as they grow. My lab partner Jordan and I wanted to use math to understand exactly how lizards spend their energy. In order to do this, we needed to measure as many of these different energy components as we could.
We began by catching 19 lizards and giving each lizard its own home in our lab. For several weeks, we weighed every cricket our lizards ate and all of the lizard poop (gross, I know!). Next, we measured the amount of energy eaten in the crickets and the amount of energy lost in their poop by exploding the poop and crickets in a machine called a calorimeter and measuring how much heat the samples gave off. (This works because heat is also a form of energy.) We then measured the energy the lizards use to stay alive with a machine called a respirometer. Last, we measured how much the lizards grew.
We repeated all of this work for all 19 lizards! In science it is important to conduct an experiment more than once, because if you only do it once and something weird happens, you’ll never know why you see the results you did. But, if you do an experiment multiple times, you will be able to tell if any of your trials were extra weird and you will have a better understanding of the pattern you are trying to study. By using 19 different lizards, we essentially redid our experiment 19 times.
Using math, we were able to come up with an explanation for how a lizard gains, loses, and uses energy. We are so excited by our results that we are now writing a paper to tell other scientists about our study. Wish us luck! 🙂